Bill Karaffa on wed 5 sep 01
-----Original Message-----
From: Ceramic Arts Discussion List [mailto:CLAYART@LSV.CERAMICS.ORG]On
Behalf Of EDGOULD
Sent: Wednesday, September 05, 2001 5:52 AM
To: CLAYART@LSV.CERAMICS.ORG
Subject: GAS KILN TEMPERATURE SLOW
"The outside of the port is 10 inches from the bagwall."
If you have a wall thickness of 9 inches (2 brick widths), this only leaves
1 inch of combustion space. I don't know what the interior dimensions of
your kiln and shelves are but I would move the bagwall out a couple of
inches if possible.
Bill Karaffa
Firemouth Pottery and Gallery
http://fp1.centurytel.net/karaffa
EDGOULD on wed 5 sep 01
I NEED MORE HELP. Thanks for the help in my last request. Using the =
damper and closing down for an hour got the heat to move up. The lower =
shelf was cone 9-10 and upper shelf was cone 6. We got the upper =
shelf to cone 9.=20
HOWEVER, THE FIRING TOOK ABOUT 17 HOURS with all 4 burners on!! After =
candling for 3 hours the kiln was brought to 600 deg. C(1112 F) between =
3 AM and 9 AM Thursday with just one burner on. Then with all 4 =
burners and two soaks close down occurred at 1:30 AM Friday morning. =
Next firing we will open up the bag wall some. =20
SOME DETAILS: Downdraft. 30 cubic ft. sprung arch. =
First shelf sits above the flu opening. Flue opening is 9x7.5 inches.
Unfortunately the flue opens into a horizontal chamber of roughly 18 =
inches before the chimney ascends. We may be losing heat and movement of =
hot air at this point. The brick chimney rises about 6 ft. to the =
level of the arch. Two steel plates permits an opening all around the =
chimney where the stainless steel 9.75 inch diameter chimney connects. =
The 9.75 inch stainless steel chimney is in three sections 3 feet =
each so the total chimney height is 6+9=3D15 feet. The 4 venturi =
burners (probably 140k btu@) enter from the sides, two on each side. =
There are no fans. I am positioning them further from the ports, at =
first half to one inch and now I will increase the distance to 1.5 to 2 =
inches to increase secondary air. The outside of the port is 10 inches =
from the bagwall. I have a 500 gallon propane tank.
ANY SUGGESTIONS ON HOW TO REDUCE FIRING TIME?
Ed Gould
Ron Roy on wed 5 sep 01
Direct flame to where you need more heat and reduction - sounds like your
bag walls should be raised.
Sounds like your flame is being drawn out the flue before it has a chance
to heat the top.
Draft too strong - slide the damper in more and open some secondary air.
RR
>I NEED MORE HELP. Thanks for the help in my last request. Using the
>damper and closing down for an hour got the heat to move up. The lower
>shelf was cone 9-10 and upper shelf was cone 6. We got the upper shelf
>to cone 9.
>
>HOWEVER, THE FIRING TOOK ABOUT 17 HOURS with all 4 burners on!! After
>candling for 3 hours the kiln was brought to 600 deg. C(1112 F) between 3
>AM and 9 AM Thursday with just one burner on. Then with all 4 burners
>and two soaks close down occurred at 1:30 AM Friday morning. Next firing
>we will open up the bag wall some.
>
>SOME DETAILS: Downdraft. 30 cubic ft. sprung arch.
>First shelf sits above the flu opening. Flue opening is 9x7.5 inches.
>Unfortunately the flue opens into a horizontal chamber of roughly 18
>inches before the chimney ascends. We may be losing heat and movement of
>hot air at this point. The brick chimney rises about 6 ft. to the level
>of the arch. Two steel plates permits an opening all around the chimney
>where the stainless steel 9.75 inch diameter chimney connects. The 9.75
>inch stainless steel chimney is in three sections 3 feet each so the
>total chimney height is 6+9=15 feet. The 4 venturi burners (probably 140k
>btu@) enter from the sides, two on each side. There are no fans. I am
>positioning them further from the ports, at first half to one inch and now
>I will increase the distance to 1.5 to 2 inches to increase secondary air.
>The outside of the port is 10 inches from the bagwall. I have a 500
>gallon propane tank.
>ANY SUGGESTIONS ON HOW TO REDUCE FIRING TIME?
>Ed Gould
Ron Roy
RR# 4
15084 Little Lake Rd..
Brighton,
Ontario, Canada
KOK 1H0
Residence 613-475-9544
Studio 613-475-3715
Fax 613-475-3513
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